Different Modes of Gas Hydrate Dissociation to Ice Observed by Microfocus X-ray Computed Tomography

To investigate the kinetics of gas hydrate dissociation to ice. We conducted in situ observations of argon, and krypton hydrates decomposed at atmospheric pressure and 245 K using microfocus X-ray computed tomography (MFXCT). The MFXCT observations for Ar samples revealed encapsulation of shirnking pure hydrate cores by ice products confirming the previously proposed model of hyrdate dissociation to ice. In stark contrast, CT images taken for Kr samples revealed entirely different distributions of the two phases: preserved hydrates homogeneously trapped in the ice matrix. Results obtained in this work indicate that the mode of hydrate dissociation to ice depends on the hydrate systems, probably because of differences in interaction between gas and water molecules.